So you’ve got your universal blueprint machine in front of you, drawn the prerequisite pentagrams, sacrificed the correct number of goats and you’ve now got your universal mover in front of you. Or in orbit – not all of these devices like being at the bottom of the gravity well.
What does it look like?
Well, there’s two major franchises I could wax lyrical about, namely the star trek matter-antimatter engines, and then the star wars fuel source… whatever that is. Fusion, I guess. But I won’t. Much.
As far as fuel supplies go, matter-antimatter is pretty awesome, if you can get enough antimatter. Regular baryonic matter is (despite it being a fraction of the known universe) relatively easy to come by, but it’s slightly more exotic twin (antimatter) is in pretty short supply, for all it is also baryonic. Perhaps at some point in the future we can learn to make the stuff – we make it now, in really, really tiny quantities – but failing some weird breakthrough, despite its zero pollution footprint, antimatter isn’t such a good idea.
Dark matter, on the other hand, is not also extremely plentiful, but appears to do odd things to normal matter. One of the prevailing theories of dark matter has it annihilating itself in a similar manner to matter and anti-matter, if so it should be relatively simple to build a dark matter engine… if we can find a way to manipulate dark matter, which, as we all know, doesn’t react to normal matter almost at all.
So we’re kind of stuck… until we look at fusion.
The less-heady alternatives to the above three (I’ll get back to fusion in a minute) are chemical rockets, ion rockets and light sails. Chemical rockets are pretty useless for a starship. They’re fine for maneuvering thrusters, but even for a jaunt as short as to Mars, they’re less than ideal. They’re heavy, they require a lot of plumbing and they’re very inefficient, for example: just to put the now out-of-commission space shuttle into earth orbit, the chemical rockets it used needed to carry 15 times that weight in fuel. To explore further than that requires a lot more.
Still, there are alternatives:
- nuclear engines (which are essentially nuclear bombs) provide a lot of thrust, with the long-dead orion program being able to lift thousands of tonnes into space in one go… but “nuclear” scares a lot of people, plus it would honestly be relatively dirty to use often.
- space elevators would take a long time to get to orbit, but would have the bonus of providing free energy for everyone if used to drag a coil through Earth’s magnetic field (this would have the downside of slowing Earth’s rotation, but we’re talking gigayears before it becomes a problem). They’re also looking more and more possible, with the work on carbon nanotubes lately.
- Laser ablation engines are a cool idea. You don’t have an engine on your ship, you just have the fuel. A separate earth-based laser ignites your fuel, and you go rocketing up into space. This solves a lot of the plumbing and weight issues, and small-scale tests actually work. Pretty cool, huh?
So, you’re in space, and you step onto the deck of your spaceship. If you’re working with something relatively realistic, you may have a fusion engine at your command. Using Helium-3, which has two protons but only the one neutron, making it lighter than ordinary helium, the resulting fusion reaction produces a proton, which can be directly used to generate electricity. Helium 3 would be very useful, as its use is essentially non-polluting, and its storage is relatively simple. It’s also relatively abundant. This, my friends, would form a very useful fuel to a space-faring people.
But… we’ve got our souped-up universal mover here, so I’d rather have a different type of engine again:
Black holes are very handy little buggers, all said and done. The old way of thinking about them was as planet-gobbling monsters, but in reality they’re kind of like stars – you can orbit a black hole safely, just the same way you can orbit a star safely. They also suck. And blow.
That was a joke, a bad one, but it’s true: black holes give off radiation called Hawking radiation. The smaller they are, the wilder they are, too. The big ones are relatively passive, but little black holes are like fizzy poppers, eating whatever you throw at them and then spitting it back out as pure energy.
That’s right, if you could properly harness a black hole, you could not only have it eat all the waste you don’t want aboard ship, but it would spit out energy for you to use to power and move your starship. If the blackhole gets too big, you starve it. If it gets too small, you feed it. It would be pretty tricky – you know, other than the sheer fact of dealing with gigatonnes worth of sucking, spitting, radioactive death – but if you mastered it, it would be a perfect energy supply and engine all rolled into one. Plus, it would give your ship a gravity gradient enabling you to not have to float about all over the place all the time.
So there you have it: if you’re building a ship this side of next millennium, you’ll probably want chemical rockets to get to orbit (at least until we can take the elevator), and once you’re up in the high frontier, you’ll probably want a fusion engine powering a ship fitted with ion rockets (which are slow to build up speed but with a top speed far higher than most anything else, so expect a bus service with ion ships constantly on the move, serviced by nippier but slower and more wasteful chemical rockets).